1. Field of the Invention
This invention relates, to a method of cutting/scoring at least one row of adjacent flat elements in a strip of material, by passing the strip between cutting/scoring cylinders of a rotary cutting machine. In particular, the invention relates to a method for solving problems which arise when at least one cutting edge or scoring line extends transversely in a straight line from one edge of the strip to the other. The invention also relates to a system for performing the method.
2. Related Art
One particular application of this invention is in the manufacture of folding boxes by the cutting and/or scoring strips of cardboard material between two cylinders, one of which carries one or more fillets that serve as cutting or scoring elements. A known problem in such an operation is that impact of the cutting or scoring fillet as the cylinders rotate generates an essentially vertical vibration which results in very slight modifications in the geometry around the cutting fillet. These modifications of the space between the cutting fillet and the adjacent cylinder, although only of the order of a few xcexcm, are sufficient to affect the quality of the cut, leaving a certain proportion of fibres uncut. The longer the cutting fillet in the direction of the cutting cylinder generatrices, the greater the impact and it becomes a maximum when the cutting fillet covers the entire width of the strip material, something which is very often the case.
These cutting impacts also constitute a considerable source of noise and are repeated high frequency.
The object of this invention is to reduce the magnitude of these impacts in order to reduce the consequences affecting the cutting quality and noise.
According to the invention, it has been found that this object can be attained by introducing slight offsets between the adjacent transverse edges or very small angles with the generatrices of the cutting cylinders. Only slight offsets are needed to give a very substantial reduction of the effects of impacts. Thus what is involved is a very simply applied operational step, but one which allows a substantial improvement to be made to the above problems.